Bonding metal



Patented July 17, 1928.

UNITED STATES ATENT OFFICE.

FREDERICK C. IYIATH-ISON, OF CHICAGO,--ILLINOIS. ASSIGNOR 0F ONE-THIRD CASPER L. REDFIELD, OF CHICAGO, ILLINOIS.

BONDING METAL.

No Drawing.

My invention relates to bonding metals, and has for its object the production of means for securing metallic bodies together in a superior manner. The present invention belongs in the same class with brazing and soldering, but differs from those processes in that it is carried out in a different manner and produces somewhat different results.

If a piece of iron or steel be immerse-.1 in an aqueous solution of copper sulphate, the iron will be immediately covered With a deposite of copper. If molten tin now be applied to the copper, either by the use of a swab or by immersing the article in the melted tin, a coating of tin will be deposited on thecopper. If a second piece of iron or steel, similarly coated with copper. be pressed against the tin coating before that coating has had time to solidify, then this copper will be bound to the tin. If the pieces of iron or steel in the above illustration be parts of a broken article, and the faces coated with copper be the fractured surfaces, then the two parts will be secured together as if they had been glued. In this case the glue consists of two'layers of copper and an intermediate layer of tin.

The above process is partly chemical, and partly the production of an alloy. IVhr-n the steel is immersed in the copper sulphate, there is an interchange of molecules. In this interchange, the iron molecules go into the solution and the copper molecules take the place of the iron ones. In this condition, the iron and copper are bound together as if they were the same body of metal.

Tinand copper unite in any proportions to form the alloys known as bronz es. and the glue of the previous illustration seems to be a bronze. The coat placed on the copper as described may be about two onethousandths of an inch in thickness. As the iron and copper do not need to be especially heated before applying the tin, the time in which the alloy is formed is very small be fore the tin solidifies. Under these conditions the alloy probably. varies from pure Application filed September 2, 1924. Serial No. 735,517.

bitt-metal. These alloys do not adhere to iron. As a consequence, in babbitting a bearing, it is necessary to use mechanical means for holding the babbitt in place. If, however, the inner face of the iron ofthe bearing be-given coats of copper and tin in the manner before described, then, in pouring the Babbitt metal into the prepared bearing box in the ordinary Way, the bab-' bitt will be bonded to the iron by the formation of an allpy at the contact face between the tin and babbitt. 7

Copper and lead do not unite to form alloys. As a consequence, lead castings may be made in copper molds. But tin alloys a copper mold is given a coating of tin as before described, or 1n any other way, and

with both copper and lead. If the inside of molten lead is poured in, then the lead will form an alloy with the tin and will be bonded to the copper. In this process, the tin forms an alloy with the copper on one side and with the lead on the other.

I have described copper as being deposited on. iron by copper sulphate. The deposit may, however, be by electro-plating. Instead of copper, I may deposit nickel or other metal on the iron. Also, I may use as a bonding metal any metal which will form an alloy Withthe metals on its opposite asides. In. this process, the alloy or alloys formed are mere films at the junction of the metals bonded, the remaining parts of those metals being unaffected by the formation of an alloy at the junction, I

Copper and zinc unite in any proportions to form alloys known as brasses. The

melting point of copper is higher than that of zinc. If a block of copper be heated to about the melting point of zinc, or a little abovethat point, and then be placed on a block of zinc, the tWo blocks will be bonded by the formation of a variable brass at the junction faces. In this process, neither body is melted, and the alloy is limited to a thin film at the junction between the bodies.

In the foregoing description I have used I the terms bond and bonding to distinguish this process from the processes of brazing and soldering. In brazing and soldering, the alloy for uniting the bodies is prepared in advance, and is applied, with the addition of a flux, by the use of a welding torch or a soldering iron. In bonding, the alloy for uniting two bodies is formed JIU melting point of the more fusible metal, but

may be below the melting point of either.

What I claim is: 1. The process of bonding a bearing metal having a lead base to an iron or steel body, Which consists in depositing a coating of copper on said body, in applying a film of tin on said copper, and in using the babbitting process to deposit the body of bearing' metal on the tinned face.

2. The process of bonding a bearing metal to an iron or steel body, which consists in applying a solution of copper sulphate to the face of the body to which the bearing metal is to be bonded, in applying a coating of molten tin to the copper deposited on the body by the first step in the process, and in using the babbitting process to deposit a body of bearing metal on the coating of tin deposited by the second step in the process FREDERICK G. MA'lHlSON. 

